ES6版本:

const angleInRadians = angleInDegrees => (angleInDegrees - 90) * (Math.PI / 180.0);

const polarToCartesian = (centerX, centerY, radius, angleInDegrees) => {
    const a = angleInRadians(angleInDegrees);
    return {
        x: centerX + (radius * Math.cos(a)),
        y: centerY + (radius * Math.sin(a)),
    };
};

const arc = (x, y, radius, startAngle, endAngle) => {
    const fullCircle = endAngle - startAngle === 360;
    const start = polarToCartesian(x, y, radius, endAngle - 0.01);
    const end = polarToCartesian(x, y, radius, startAngle);
    const arcSweep = endAngle - startAngle <= 180 ? '0' : '1';

    const d = [
        'M', start.x, start.y,
        'A', radius, radius, 0, arcSweep, 0, end.x, end.y,
        fullCircle ? 'Z':''
    ].join(' ');

    return d;
};

对@opsb的回答稍加修改。我们不能用这种方法画一个完整的圆。如果我们给(0,360)它什么也画不出来。所以做了一点小小的修改来解决这个问题。显示有时达到100%的分数可能很有用。

function polarToCartesian(centerX, centerY, radius, angleInDegrees) {
  var angleInRadians = (angleInDegrees-90) * Math.PI / 180.0;

  return {
    x: centerX + (radius * Math.cos(angleInRadians)),
    y: centerY + (radius * Math.sin(angleInRadians))
  };
}

function describeArc(x, y, radius, startAngle, endAngle){

    var endAngleOriginal = endAngle;
    if(endAngleOriginal - startAngle === 360){
        endAngle = 359;
    }

    var start = polarToCartesian(x, y, radius, endAngle);
    var end = polarToCartesian(x, y, radius, startAngle);

    var arcSweep = endAngle - startAngle <= 180 ? "0" : "1";

    if(endAngleOriginal - startAngle === 360){
        var d = [
              "M", start.x, start.y, 
              "A", radius, radius, 0, arcSweep, 0, end.x, end.y, "z"
        ].join(" ");
    }
    else{
      var d = [
          "M", start.x, start.y, 
          "A", radius, radius, 0, arcSweep, 0, end.x, end.y
      ].join(" ");
    }

    return d;       
}

document.getElementById("arc1").setAttribute("d", describeArc(120, 120, 100, 0, 359));

我稍微修改了opsb的答案，并在圆形扇区的支持填充中进行了修改。 http://codepen.io/anon/pen/AkoGx

JS

function polarToCartesian(centerX, centerY, radius, angleInDegrees) {
  var angleInRadians = (angleInDegrees-90) * Math.PI / 180.0;

  return {
    x: centerX + (radius * Math.cos(angleInRadians)),
    y: centerY + (radius * Math.sin(angleInRadians))
  };
}

function describeArc(x, y, radius, startAngle, endAngle){

    var start = polarToCartesian(x, y, radius, endAngle);
    var end = polarToCartesian(x, y, radius, startAngle);

    var arcSweep = endAngle - startAngle <= 180 ? "0" : "1";

    var d = [
        "M", start.x, start.y, 
        "A", radius, radius, 0, arcSweep, 0, end.x, end.y,
        "L", x,y,
        "L", start.x, start.y
    ].join(" ");

    return d;       
}

document.getElementById("arc1").setAttribute("d", describeArc(200, 400, 100, 0, 220));

HTML

<svg>
  <path id="arc1" fill="orange" stroke="#446688" stroke-width="0" />
</svg>

@opsb的回答很简洁，但中心点不准确，而且，正如@Jithin指出的那样，如果角度是360，那么什么都画不出来。

@Jithin修复了360度的问题，但如果你选择小于360度，那么你会得到一条线关闭弧环，这是不需要的。

我修复了这个问题，并在下面的代码中添加了一些动画:

function myArc(cx, cy, radius, max){ var circle = document.getElementById("arc"); var e = circle.getAttribute("d"); var d = " M "+ (cx + radius) + " " + cy; var angle=0; window.timer = window.setInterval( function() { var radians= angle * (Math.PI / 180); // convert degree to radians var x = cx + Math.cos(radians) * radius; var y = cy + Math.sin(radians) * radius; d += " L "+x + " " + y; circle.setAttribute("d", d) if(angle==max)window.clearInterval(window.timer); angle++; } ,5) } myArc(110, 110, 100, 360); <svg xmlns="http://www.w3.org/2000/svg" style="width:220; height:220;"> <path d="" id="arc" fill="none" stroke="red" stroke-width="2" /> </svg>

我会使用其他答案的代码，它们看起来都是互相复制的，但是我会让起点是开始角度的函数而终点是结束角度的函数。

我将使用绝对值使大圆弧标志与顺序无关，并通过360度模数使角度与数值大小无关。

var start = polarToCartesian(x, y, radius, startAngle);
var end = polarToCartesian(x, y, radius,   endAngle);

largeArcFlag = Math.abs((endAngle - startAngle) % 360) <= 180 ? "0" : "1";
clockwiseFlag = (endAngle > startAngle) ? "1" : "0";

var d = [
    "M", start.x, start.y, 
    "A", radius, radius, 0, largeArcFlag, clockwiseFlag, end.x, end.y
  ].join(" ");

向威利道歉;我还没读到最后，他也发现了同样的事情。如果你喜欢我的帖子，就给他投票吧!

基于所选答案的ReactJS组件:

import React from 'react';

const polarToCartesian = (centerX, centerY, radius, angleInDegrees) => {
    const angleInRadians = (angleInDegrees - 90) * Math.PI / 180.0;

    return {
        x: centerX + (radius * Math.cos(angleInRadians)),
        y: centerY + (radius * Math.sin(angleInRadians))
    };
};

const describeSlice = (x, y, radius, startAngle, endAngle) => {

    const start = polarToCartesian(x, y, radius, endAngle);
    const end = polarToCartesian(x, y, radius, startAngle);

    const largeArcFlag = endAngle - startAngle <= 180 ? "0" : "1";

    const d = [
        "M", 0, 0, start.x, start.y,
        "A", radius, radius, 0, largeArcFlag, 0, end.x, end.y
    ].join(" ");

    return d;
};

const path = (degrees = 90, radius = 10) => {
    return describeSlice(0, 0, radius, 0, degrees) + 'Z';
};

export const Arc = (props) => <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300">
    <g transform="translate(150,150)" stroke="#000" strokeWidth="2">
        <path d={path(props.degrees, props.radius)} fill="#333"/>
    </g>

</svg>;

export default Arc;